changeset:   92768:e70b2b8ffe02
branch:      counter_lt
tag:         tip
parent:      88635:9bbb64e91913
user:        Ram Rachum <ram@rachum.com>
date:        Fri Oct 03 12:02:02 2014 +0300
summary:     Counter comparison

diff -r 9bbb64e91913 -r e70b2b8ffe02 Lib/collections/__init__.py
--- a/Lib/collections/__init__.py	Wed Jan 22 03:05:49 2014 -0800
+++ b/Lib/collections/__init__.py	Fri Oct 03 12:02:02 2014 +0300
@@ -751,6 +751,73 @@
             if other_count < count:
                 self[elem] = other_count
         return self._keep_positive()
+    
+    
+    def __lt__(self, other):
+        if not isinstance(other, Mapping):
+            raise TypeError("Can't compare %s to non-mapping %s" %
+                            (type(self).__name__, type(other).__name__))
+        found_strict_difference = False # Until challenged.
+        for element, count in self.items():
+            try:
+                other_count = other[element]
+            except KeyError:
+                if count > 0:
+                    return False
+            if not (count <= other_count):
+                return False
+            elif count < other_count:
+                found_strict_difference = True
+        
+        return found_strict_difference
+    
+    def __le__(self, other):
+        if not isinstance(other, Mapping):
+            raise TypeError("Can't compare %s to non-mapping %s" %
+                            (type(self).__name__, type(other).__name__))
+        for element, count in self.items():
+            try:
+                other_count = other[element]
+            except KeyError:
+                if count > 0:
+                    return False
+            if not (count <= other_count):
+                return False
+        
+        return True
+    
+    def __gt__(self, other):
+        if not isinstance(other, Mapping):
+            raise TypeError("Can't compare %s to non-mapping %s" %
+                            (type(self).__name__, type(other).__name__))
+        found_strict_difference = False # Until challenged.
+        for element, count in self.items():
+            try:
+                other_count = other[element]
+            except KeyError:
+                continue
+            if not (count >= other_count):
+                return False
+            elif count > other_count:
+                found_strict_difference = True
+        
+        return found_strict_difference
+    
+    def __ge__(self, other):
+        if not isinstance(other, Mapping):
+            raise TypeError("Can't compare %s to non-mapping %s" %
+                            (type(self).__name__, type(other).__name__))
+        for element, count in self.items():
+            try:
+                other_count = other[element]
+            except KeyError:
+                continue
+            if not (count >= other_count):
+                return False
+        
+        return True
+    
+    
 
 
 ########################################################################
diff -r 9bbb64e91913 -r e70b2b8ffe02 Lib/test/test_collections.py
--- a/Lib/test/test_collections.py	Wed Jan 22 03:05:49 2014 -0800
+++ b/Lib/test/test_collections.py	Fri Oct 03 12:02:02 2014 +0300
@@ -1084,6 +1084,51 @@
         c = CounterSubclassWithGet('abracadabra')
         self.assertTrue(c.called)
         self.assertEqual(dict(c), {'a': 5, 'b': 2, 'c': 1, 'd': 1, 'r':2 })
+        
+    def test_comparison(self):
+        import decimal
+        
+        counter_0 = Counter('c')
+        counter_1 = Counter('abc')
+        counter_2 = Counter('aabc')
+        counter_3 = Counter('abbc')
+        counter_4 = Counter('aabbcc')
+        d = {'a': 1.5, 'b': 1.0, 'c': decimal.Decimal('1.0'),
+             'd': float('inf'),}
+        
+        bad_d = {'a': 'a'}
+        
+        hierarchy = (
+            (d, {counter_1}),
+            (counter_4, {d, counter_3, counter_2, counter_1, counter_0}),
+            (counter_3, {counter_1, counter_0}),
+            (counter_2, {counter_1, counter_0}),
+            (counter_1, {counter_0}),
+            (counter_0, set()),
+        )
+        
+        for item, smaller_items in hierarchy:
+            if not isinstance(item, Counter):
+                continue
+            for smaller_item in smaller_items:
+                assert not item <= smaller_item
+                assert not item < smaller_item
+                assert item >= smaller_item
+                assert item > smaller_item
+                assert item != smaller_item
+            not_smaller_items = [item for item in zip(*hierarchy)[0] if
+                                                      item not in smaller_item]
+            for not_smaller_item in not_smaller_items:
+                assert not item < smaller_item
+                
+            with self.assertRaises(TypeError):
+                item <= bad_d
+            with self.assertRaises(TypeError):
+                item < bad_d
+            with self.assertRaises(TypeError):
+                item >= bad_d
+            with self.assertRaises(TypeError):
+                item > bad_d
 
 
 ################################################################################